Head position detecting device and head tracking stereoscopic display

1. A head tracking stereoscopic display comprising: light emitting means comprising at least two combining light sources, each combining light source comprised of a set of two line-shaped light sources for one of the eyes and the other eye, the two line-shaped light sources being for a first area and a second area in a position shifted by approximately E/2 (E is the distance between the eyes of a viewer) in the horizontal direction from the first area; a diffusing screen provided on the light emission side of said light emitting means; a first lenticular long screen provided between said diffusing screen and the light emitting means for focusing light from a selected one of the line-shaped light sources and alternately forming bright portions and dark portions on said diffusing screen by semi-cylindrical lens portions constituting the first lenticular lens screen; a second lenticular lens screen provided on the light emission side of said diffusing screen and having the function of taking each of said bright portions formed on the diffusing screen as a light source for either one of the eyes; an image display panel provided on the light emission side of the second lenticular lens screen; light source control means for alternately turning one of the line-shaped light sources and the other line-shaped light source in a selected one combining light source on and off; display control means for alternately displaying one of the images and the other image which have binocular parallax on said image display panel in synchronization with an alternate ON/OFF of said line-shaped light sources; head position detection means for detecting the position of the head of the viewer; and control means for carrying out control as to change the timing of an alternate display of the images and select the line-shaped light sources on the basis of information relating to the head position from said head position detection means, wherein said control means is constructed to carry out control, letting n be an integer, E be the distance between the eyes of the viewer, and A be the horizontal distance from the center of a stereoscopic position right in front of a screen, to perform basic processing in selecting the timing of the alternate display of the images and the combining light sources when the viewer is in an area indicated by (2n-1/2).times.E.ltoreq.A.ltoreq.(2n+1/2).times.E on the basis of the center of the stereoscopic position right in front of the screen, while changing the timing of the alternate display of one of the images and the other image which have binocular parallax using as a light source to be selected the line-shaped light sources for the first area as it is when the viewer moves to an area indicated by {(2n+1)-1/2}.times.E<A<{(2n+1)+1/2}.times.E.

2. The head tracking stereoscopic display according to claim 1, wherein said control means is constructed to carry out control, letting n be an integer, E be the distance between the eyes of the viewer, and A be the horizontal distance from the center of a stereoscopic position right in front of a screen, as to select the two-lined light sources for the second area and suitably change or maintain the alternate display when the viewer moves to an area indicated by {(1+2n)/2-1/4}.times.E<A<{(1+2n)/2+1/4}.times.E on the basis of the center of the stereoscopic position right in front of the screen.

3. A head tracking stereoscopic display comprising: light emitting means comprising at least two combining light sources each combining light source comprised of a set of two line-shaped light sources for one of the eyes and the other eye, the two line-shaped light sources being for a first area and a second area in a position shifted by approximately E/2 (E is the distance between the eyes of a viewer) in the horizontal direction from the first area; a diffusing screen provided on the light emission side of said light emitting means; a first lenticular lens screen provided between said diffusing screen and the light emitting means for focusing light from a selected one of the line-shaped light sources and alternately forming bright portions and dark portions on said diffusing screen by semi-cylindrical lens portions constituting the first lenticular lens screen; a second lenticular lens screen provided on the light emission side of said diffusing screen and having the function of taking each of said bright portions formed on the diffusing screen as a light source for either one of the eyes; an image display panel provided on the light emission side of the second lenticular lens screen; light source control means for alternately turning one of the line-shaped light sources and the other line-shaped light source in a selected one combining light source on and off; display control means for alternately displaying one of the images and the other image which have binocular parallax on said image display panel in synchronization with an alternate ON/OFF of said line-shaped light sources; head position detection means for detecting the position of the head of the viewer; and control means for carrying out control as to change the timing of an alternate display of the images and select the line-shaped light sources on the basis of information relating to the head position from said head position detection means, wherein letting E be the distance between the eyes of the viewer, H be the distance between the viewer and the second lenticular lens screen, J be the distance between the second lenticular lens screen and the diffusing screen, L be the distance between the diffusing screen and the first lenticular lens screen, and K be the distance between the first lenticular lens screen and the light emitting means, the pitch S between the line-shaped light sources in each of the combining light sources satisfies the following equation: EQU S=K.times.E.times.J/(L.times.H).

4. The head tracking stereoscopic display according to claim 3, wherein letting F be the focal length of each of semi-cylindrical lens portions constituting the second lenticular lens screen, and G be the focal length of each of the semi-cylindrical lens portions constituting the first lenticular lens screen, the following equations are satisfied: EQU F=J.times.H/(H-J) EQU G=L.times.K/(K-L).

5. The head tracking stereoscopic display according to claim 3, wherein letting P be the pitch between the semi-cylindrical lens portions constituting the second lenticular lens screen, and Q be the pitch between the semi-cylindrical lens portions constituting the first lenticular lens screen, the following equations are satisfied: EQU P=2.times.E.times.J/(J+H) EQU Q=2.times.K.times.E.times.J/(H.times.(L+K)).

6. The head tracking stereoscopic display according to claim 3, wherein letting n be an integer, the pitch between the combining light sources satisfies (n+1/2).times.S.

7. A head tracking stereoscopic display comprising: two one-eye systems each comprising light emitting means comprising a first light source comprised of a set of two line-shaped light sources and a second light source comprised of the other set of two line-shaped light sources, a diffusing screen provided on the light emission side of said light emitting means, a first lenticular lens screen provided between said diffusing screen and the light emitting means for focusing light from a selected one of the line-shaped light sources and alternately forming bright portions and dark portions on said diffusing screen by semi-cylindrical lens portions constituting the first lenticular lens screen, a second lenticular lens screen provided on the light emission side of said diffusing screen and having the function of taking each of said bright portions formed on the diffusing screen as a light source for either one of the eyes, and an image display panel provided on the light emission side of the second lenticular lens screen; image supply means for fixedly displaying one of images and the other image which have binocular parallax, respectively, on the image display panel in one of the one-eye systems and the image display panel in the other one-eye system; head position detection means for detecting the position of the head of a viewer; and control means for carrying out control to select light emission of the line-shaped light sources in said first and second light sources on the basis of information relating to the head position from said head position detection means, wherein said control means is constructed to carry out control, letting n be an integer, E be the distance between the eyes of the viewer, and A be the horizontal distance from the center of a stereoscopic position right in front of a screen, to select one of the line-shaped light sources in the first light source when the viewer is in an area indicated by (2n-1/2).times.E.ltoreq.A.ltoreq.(2n+1/2).times.E on the basis of the center of the stereoscopic position right in front of the screen, while selecting the other line-shaped light source in the first light source when the viewer moves to an area indicated by {(2n+1)-1/2}.times.E<A<{(2n+1)+1/2}.times.E.

8. The head tracking stereoscopic display according to claim 7, wherein said control means is constructed to carry out control, letting n be an integer, E be the distance between the eyes of the viewer, and A be the horizontal distance from the center of a stereoscopic position right in front of a screen, to suitably select either one of the two line-shaped light sources in the second light source when the viewer moves to an area indicated by {(1+2n)/2-1/4}.times.E<A<{(1+2n)/2+1/4}.times.E on the basis of the center of the stereoscopic position right in front of the screen.

9. A head tracking stereoscopic display comprising: two one-eye systems each comprising light emitting means comprising a first light source comprised of a set of two line-shaped light sources and a second light source comprised of the other set of two line-shaped light sources, a diffusing screen provided on the light emission side of said light emitting means, a first lenticular lens screen provided between said diffusing screen and the light emitting means for focusing light from a selected one of the line-shaped light sources and alternately forming bright portions and dark portions on said diffusing screen by semi-cylindrical lens portions constituting the first lenticular lens screen, a second lenticular lens screen provided on the light emission side of said diffusing screen and having the function of taking each of said bright portions formed on the diffusing screen as a light source for either one of the eyes, and an image display panel provided on the light emission side of the second lenticular lens screen; image supply means for fixedly displaying one of images and the other image which have binocular parallax, respectively, on the image display panel in one of the one-eye systems and the image display panel in the other one-eye system; head position detection means for detecting the position of the head of a viewer; and control means for carrying out control to select light emission of the line-shaped light sources in said first and second light sources on the basis of information relating to the head position from said head position detection means, wherein letting E be the distance between the eyes of a viewer, and H be the distance between the viewer and the second lenticular lens screen, J be the distance between the second lenticular lens screen and the diffusing screen, L be the distance between the diffusing screen and the first lenticular lens screen, and K be the distance between the first lenticular lens screen and the light emitting means in each of the one-eye systems, the pitch S between the line-shaped light sources in each of the light sources satisfies the following equation: EQU S=K.times.E.times.J/(L.times.H).

10. The head tracking stereoscopic display according to claim 9, wherein letting F be the focal length of each of the semi-cylindrical lens portions constituting the second lenticular lens screen, and G be the focal length of each of semi-cylindrical lens portions constituting the first lenticular lens screen in each of the one-eye systems, the following equations are satisfied: EQU F=J.times.H/(H-J) EQU G=L.times.K/(K-L).

11. The head tracking stereoscopic display according to claim 9, wherein letting P be the pitch between the semi-cylindrical lens portions constituting the second lenticular lens screen, and Q be the pitch between the semi-cylindrical lens portions constituting the first lenticular lens screen in each of the one-eye systems, the following equations are satisfied: EQU P=2.times.E.times.J/(J+H) EQU Q=2.times.K.times.E.times.J/(H.times.(L+K)).

12. The head tracking stereoscopic display according to claim 9, wherein letting n be an integer, the pitch between the light sources satisfies (n+1/2).times.S.

13. A head tracking stereoscopic display comprising: two one-eye systems each comprising light emitting means comprising a line-shaped light source for a first area and a line-shaped light source for a second area in a position shifted by approximately E/2 (E is the distance between the eyes of a viewer) in the horizontal direction from the first areas, a diffusing screen provided on the light emission side of said light emitting means, a first lenticular lens screen provided between said diffusing screen and the light emitting means for focusing light from a selected one of the line-shaped light sources and alternately forming bright portions and dark portions on said diffusing screen by semi-cylindrical lens portions constituting the first lenticular lens screen, a second lenticular lens screen provided on the light emission side of said diffusing screen and having the function of taking each of said bright portions formed on the diffusing screen as a light source for either one of the eyes, and an image display panel provided on the light emission side of the second lenticular lens screen; image supply means for respectively displaying one of images and the other image which have binocular parallax on the image display panel in one of the one-eye systems and the image display panel in the other one-eye system so as to be switchable; head position detection means for detecting the position of the head of the viewer; and control means for carrying out control to select light emission of the line-shaped light sources and switch the images displayed on said image display panel on the basis of information relating to the head position from said head position detection means, wherein said control means is constructed to carry out control, letting n be an integer, E be the distance between the eyes of the viewer, and A be the horizontal distance from the center of a stereoscopic position right in front of a screen, to select the line-shaped light source for the first area when the viewer is in an area indicated by (2n-1/2).times.E.ltoreq.A.ltoreq.(2n+1/2).times.E on the basis of the center of the stereoscopic position right in front of the screen, while selecting the line-shaped light source for the first area and switching the images displayed on said image display panel when the viewer moves to an area indicated by {(2n+1)-1/2}.times.E<A<{(2n+1)+1/2}.times.E.

14. The head tracking stereoscopic display according to claim 13, wherein said control means is constructed to carry out control, letting n be an integer, E be the distance between the eyes of the viewer, and A be the horizontal distance from the center of a stereoscopic position right in front of a screen, to select the line-shaped light source for the second area and suitably switch the images displayed on said image display panel when the viewer moves to an area indicated by {(1+2n)/2-1/4}.times.E<A<{(1+2n)/2+1/4}.times.E on the basis of the center of the stereoscopic position right in front of the screen.

15. A head tracking stereoscopic display comprising: two one-eye systems each comprising light emitting means comprising a line-shaped light source for a first area and a line-shaped light source for a second area in a position shifted by approximately E/2 (E is the distance between the eyes of a viewer) in the horizontal direction from the first area, a diffusing screen provided on the light emission side of said light emitting means, a first lenticular lens screen provided between said diffusing screen and the light emitting means for focusing light from a selected one of the line-shaped light sources and alternately forming bright portions and dark portions on said diffusing screen by semi-cylindrical lens portions constituting the first lenticular lens screen, a second lenticular lens screen provided on the light emission side of said diffusing screen and having the function of taking each of said bright portions formed on the diffusing screen as a light source for either one of the eyes, and an image display panel provided on the light emission side of the second lenticular lens screen; image supply means for respectively displaying one of images and the other image which have binocular parallax on the image display panel in one of the one-eye systems and the image display panel in the other one-eye system so as to be switchable; head position detection means for detecting the position of the head of the viewer; and control means for carrying out control to select light emission of the line-shaped light sources and switch the images displayed on said image display panel on the basis of information relating to the head position from said head position detection means, wherein letting E be the distance between the eyes of the viewer, and letting H be the distance between the viewer and the second lenticular lens screen, J be the distance between the second lenticular lens screen and the diffusing screen, L be the distance between the diffusing screen and the first lenticular lens screen, and K be the distance between the first lenticular lens screen and the light emitting means in each of the one-eye systems, the width M of each of the line-shaped light sources satisfies the following equation: EQU M=K.times.E.times.J/(L.times.H).

16. The head tracking stereoscopic display according to claim 15, wherein letting F be the focal length of each of the semi-cylindrical lens portions constituting the second lenticular lens screen, and G be the focal length of each of the semi-cylindrical lens portions constituting the first lenticular lens screen in each of the one-eye systems, the following equations are satisfied: EQU F=J.times.H/(H-J) EQU G=L.times.K/(K-L).

17. The head tracking stereoscopic display according to claim 15, wherein letting P be the pitch between the semi-cylindrical lens portions constituting the second lenticular lens screen, and Q be the pitch between the semi-cylindrical lens portions constituting the first lenticular lens screen in each of the one-eye systems, the following equations are satisfied: EQU P=2.times.E.times.J/(J+H) EQU Q=2.times.K.times.E.times.J/(H.times.(L+K)).

18. The head tracking stereoscopic display according to claim 15, wherein letting n be an integer, the pitch between the line-shaped light sources satisfies (n+1/2).times.M.

19. A head position detecting device comprising: light receiving means constructed by arranging a first light receiving device for a stereoscopic area and a second light receiving device for a pseudostereoscopic area in the horizontal direction, lens means for respectively introducing light reflected from the face of a viewer positioned in the stereoscopic area and light reflected from the face of the viewer positioned in the pseudostereoscopic area into said first light receiving device and said second light receiving device; and judgment means for comparing the amount of the light detected in said first light receiving device and the amount of the light detected in said second light receiving device, to judge which of the stereoscopic area and the pseudostereoscopic area is an area where the viewer is positioned.

20. The head position detecting device according to claim 19, wherein letting E be the distance between the eyes, A1 be the distance between said lens means and the viewer, B1 be the distance between said lens means and said light receiving means, and P1 be the pitch between the first light receiving device and the second light receiving device, the following equation is satisfied: EQU P1=E.times.B1/A1.

21. The head position detecting device according to claim 19, wherein letting E be the distance between the eyes of the viewer, A1 be the distance between said lens means and the viewer, B1 be the distance between said lens means and said light receiving means, and Q1 be the pitch between the lens means, the following equation is satisfied: EQU Q1=2.times.E.times.B1/(A1+B1).

22. The head position detecting device according to claim 19, wherein letting E be the distance between the eyes of the viewer, A1 be the distance between said lens means and the viewer, B1 be the distance between said lens means and said light receiving means, and F1 be the focal length of said lens means, the following equation is satisfied: EQU F1=A1.times.B1/(A1+B1).

23. The head position detecting device according to claim 19, wherein a plurality of lens means are arranged in the horizontal direction.

24. The head position detecting device according to claim 23, wherein a lenticular lens is used as the plurality of lens means arranged in the horizontal direction.

25. A head position detecting device comprising: light receiving means constructed by arranging a first light receiving device for a stereoscopic area, a second light receiving device for a pseudostereoscopic area, a third light receiving device for a first crosstalk area, and a fourth light receiving device for a second crosstalk area in the horizontal direction; lens means for respectively introducing light reflected from the face of a viewer positioned in the stereoscopic area, light reflected from the face of the viewer positioned in the pseudostereoscopic area, light reflected from the face of the viewer positioned in the first crosstalk area, and light reflected from the face of the viewer positioned in the second crosstalk area into said first light receiving device, said second light receiving device, said third light receiving device, and said fourth light receiving device; and judgment means for comparing the amount of the light detected in said first light receiving device, the amount of the light detected in said second light receiving device, the amount of the light detected in said third light receiving device, and the amount of the light detected in said fourth light receiving device, to judge which of the stereoscopic area, the pseudostereoscopic area, the first crosstalk area, and the second crosstalk area is an area where the viewer is positioned.

26. The head position detecting device according to claim 25, wherein letting E be the distance between the eyes of the viewer, A2 be the distance between said lens means and the viewer, B2 be the distance between said lens means and said light receiving means, and P2 be the pitch between the light receiving devices, the following equation is satisfied: EQU P2=E.times.B2/(2.times.A2).

27. The head position detecting device according to claim 25, wherein letting E be the distance between the eyes of the viewer, A2 be the distance between said lens means and the viewer, B2 be the distance between said lens means and said light receiving means, and Q2 be the pitch between the lens means, the following equation is satisfied: EQU Q2=2.times.E.times.B2/(A2+B2).

28. The head position detecting device according to claim 25, wherein letting E be the distance between the eyes of the viewer, A2 be the distance between said lens means and the viewer, B2 be the distance between said lens means and said light receiving means, and F2 be the focal length of said lens means, the following equation is satisfied: EQU F2=A2.times.B2/(A2+B2).

29. The head position detecting device according to claim 25, wherein a plurality of lens means are arranged in the horizontal direction.

30. The head position detecting device according to claim 29, wherein a lenticular lens is used as the plurality of lens means arranged in the horizontal direction.

31. A head tracking stereoscopic display comprising: a head position detecting device comprising light receiving means constructed by arranging a first light receiving device for a stereoscopic area and a second light receiving device for a pseudostereoscopic area in the horizontal direction, lens means for respectively introducing light reflected from the face of a viewer positioned in the stereoscopic area and light reflected from the face of the viewer positioned in the pseudostereoscopic area into said first light receiving device and said second light receiving device, and judgment means for comparing the amount of the light detected in said first light receiving device and the amount of the light detected in said second light receiving device, to judge which of the stereoscopic area and the pseudostereoscopic area is an area where the viewer is positioned, the head tracking stereoscopic display being constructed to respectively introduce a right eye image and a left eye image to the right eye and the left eye of the viewer positioned in the stereoscopic area when a signal indicating that the viewer is positioned in the stereoscopic area is obtained in said head position detecting device, and constructed to respectively introduce the right eye image and the left eye image to the right eye and the left eye of the viewer positioned in the pseudostereoscopic area when a signal indicating that the viewer is positioned in the pseudostereoscopic area is obtained.

32. A head tracking stereoscopic display comprising: a head position detecting device comprising light receiving means constructed by arranging a first light receiving device for a stereoscopic area, a second light receiving device for a pseudostereoscopic area, a third light receiving device for a first crosstalk area, and a fourth light receiving device for a second crosstalk area in the horizontal direction, lens means for respectively introducing light reflected from the face of a viewer positioned in the stereoscopic area, light reflected from the face of the viewer positioned in the pseudostereoscopic area, light reflected from the face of the viewer positioned in the first crosstalk area, and light reflected from the face of the viewer positioned in the second crosstalk area into said first light receiving device, said second light receiving device, said third light receiving device, and said fourth light receiving device, and judgment means for comparing the amount of the light detected in said first light receiving device, the amount of the light detected in said second light receiving device, the amount of the light detected in said third light receiving device, and the amount of the light detected in said fourth light receiving device, to judge which of the stereoscopic area, the pseudostereoscopic area, the first crosstalk area, and the second crosstalk area is an area where the viewer is positioned, the head tracking stereoscopic display being constructed to respectively introduce a right eye image and a left eye image to the right eye and the left eye of the viewer positioned in the stereoscopic area when a signal indicating that the viewer is positioned in the stereoscopic area is obtained in said head position detecting device, constructed to respectively introduce the right eye image and the left eye image to the right eye and the left eye of the viewer positioned in the pseudostereoscopic area when a signal indicating that the viewer is positioned in the pseudostereoscopic area is obtained, constructed to respectively introduce a right eye image and a left eye image to the right eye and the left eye of the viewer positioned in the first crosstalk area when a signal indicating that the viewer is positioned in the first crosstalk area is obtained, and constructed to respectively introduce the right eye image and the left eye image to the right eye and the left eye of the viewer positioned in the second crosstalk area when a signal indicating that the viewer is positioned in the second crosstalk area is obtained.